Peeling knife



July 12, 1938. M. EWALD 2,123,187

- FEELING KNIFE Original Filed Oct. 26, 1934 FIG.\

UNITED STATES] PATENT OFFICE PEELING KNIFE Mark Ewald, Olympia, Wash., assignor to Special Equipment Company, Portland, reg., a corporation of Oregon Application October 26, 1934, Serial No. 750,151. Renewed September 20, 1937 2 Claims (01. 146--43) This invention has to do with a device for the an axis in a plane defined by the cutting edge treating of fruit preparatory to canning and rethereof. lates particularly to a turnable knife adapted to An improved knife of a metal strip deformed remove the peel from the fruit. into the shape of a longitudinal element extend- The peeling knife manufactured in the maning antipodally of the surface of a pear or other ner hereinafter disclosed, is adapted to cooper fruit and rotatable about an axis coinciding with ate with a fruit holding cup for-removing the the center of curvature of the inner face of the epidermis from a half fruit held within the cup knife. in a manner exposing the fiat severed face-and These objects and such other objects as may It with the epidermis engaging the cup walls, which hereinafter appear .are obtained by the novel latter conform generally to the periphery of the construction, unique arrangement, and improved fruit. The knife is disposedfor rotation about combination of elements illustrated in the ac an axis substantially within the plane faceof companyingsheet of drawing, hereby made a the fruit to carry its thin ribbon-like body along part 'of this application, and in which:

" the inner side of the walls of the cup and through Figure 1 is a plan view of a blank of metal from 15 the meat of the fruit just beneath the surface of which the improved knife may be made; the epidermis. Figure 2 is, a side view of the blank of Figure Foran understanding of a cup in which the 1 subsequent to it being distorted to approximate knife here described is useful, reference may be the shape of the finished article; gtj had to the copending application of Mark Ewald, Figure 3 is a. transverse sectional view of the go serially numbered 63,019 filed February 8, 1935,- unfinished knife taken at the line 3-3 of Fig the same being a continuation of 627,549, filed ure 2; August 5, 1932, entitled Fruit holding cup, and Figure 4 is a view similar to Figure 3 but after of which application the present is a continuaa partialsharpeningof the knife;

tion in part. The cup structure is claimed in Figure 5 is a fragmentary view of the finished 25 such application, Serial No. 627,549. knife, showing. the manner of attachment to A complete knowledge of the machine with means for its rotation; which the present invention is adapted to be Figurefi is a left side view of the parts shown combined may be had by referring to a co-pendin Figure 5.

ing application of Mark Ewald, serially num- Like reference characters are used to designate 3 bered 636,447, filed Octoberfi, 1932, and entitled similar parts in the drawing and in the descrip- Pear treating apparatus. tion of the invention which follows.

Reference is had to my prior application, Serial, The blank from which blade I0 is made No. 711,354, filed February 15, 1934, issued as is shown; at the initial stage of its manufacture 5 Patent No. 2,060,802 on November 17, 1936, entiin Figure 1. Such blank is in the form of a long. 1 tled Process of knife manufacture, whereof the rather narrow strip H of suitable metal. The present application is a division. Suchpatent thickness of the strip II depends upon its length contains claims to the process of making the and the size desired in the finished article. At knife per se. In addition, reference is also made present knives like the one illustrated are made I to my prior application, Serial No. 750,152,. now in four sizes, the material being stainless cutlery 40' pending, filed October 26, 1934, and entitled. steel. In the smallest size of knife, the steel strip Process of peeling, which latter application is. ll generally is .042 of an inch in thickness. In also a division of application 711,354.. Claims the largest of the four sizes of knives, the metal in application 750,152.are made. tothe process. strip ll generally has an original thickness of involved in peeling the fruit by the cooperation. .065 of an inch. 5 ofthe improved knife of the present application After thestrip H has been obtained, as by and the specific cup structure disclosed in said shearing or stamping it from a. larger piece of application 750,152. sheet material, the stripis subjected. to the action Among the objects of the present invention is, of complemental swaging tools whereby it is dethe provision of: formed longitudinally into the shape illustrated 5'0 An improved form of peeling knife adaptedtd, in Figure2. In addition to the longitudinal curbe passed beneath the peel-of a fruit 'witha Sins. vature given to the blade, shown in Figure 2, the gle rotative movement without mutilating the blank. is given a, slight curve transversely of its fruit. body, as shown in Figure 3. In Figures 2, 3 and Anew peeling knife designed for rotation about 4, the axis of rotation of the blade, when it is 55 finished, is indicated by a broken line and dot designated by the character A. The axis coincides substantially with an edge of the blade, such edge being the cutting edge. The transverse curvature of the blade is such that the body of the blade at all points except the outer face of the cutting edge substantially is concentric to the axis A. Such is true for the whole iength of that section of the blade lying to one side of the axis of rotation.

Figure 4 is a View similar to Figure 3 but illustrates the unfinished blade after it has been partly ground (i3) along its leading edge if. In forming the section 53, which is coextensive with sections it, I5 and E6 of the blade, about twothirds the thickness of the material is removed at the lower part or" the leading edge if, the face extending backwardly about one-third of the width of the blade. At this time notches i"! may be formed at opposite ends of the blade to facili tate attachment to blocks if; for rotation, one block being shown in Figures 5 and 6.

The notches ii are so placed that the axis A of the blade will coincide with the center of a shaft opening iii in each of the blocks 53, such openings receiving shafts 253 for rotating the blocks 58.

After the face l3 and the notches ll have been formed in the blank, the blade is subjected to a suitable heat treatment for tempering. A satisfactory heat treating process has been found to include the steps of heating the blade to 1725 Fahrenheit, then quenching in oil and leaving the article in oil of 400 Fahrenheit for a short period of time. This being done, the knife is placed in a suitable device, not shown, for oscillating it about axis A while a small grinding member is moved back and forth along its inner face. In this manner, the inner face of the blade is given a surface which at all points focuses truly upon the axis A of rotation.

Next, the face of the outer section 13 of the blade is rounded as shown in Figure 5 adjacent the leading edge 52 thereof so that the outer face converges upon the inner face and forms a cutting edge, the cutting edge being substantially flush with the inner face. Figure 5 illustrates a cross section of a finished blade intermediate its length.

It will thus be seen that I have provided a knife, the inner face of which is concave transversely of the length of the knife whereby the blade is adapted to glide substantially freely along the periphery of the portion of the fruit from which the peel has been severed. It will also be observed that the inner face of my improved knife is curved in a direction transversely of the length of the knife so that all points thereof are equi-distant from the axis of rotation of the knife whereby to prevent bruising o1 squeezing of the fruit during the peeling operation.

It will also be observed that the bevel of the blade is on the outer face of the knife. It will also be apparent that I have provided a knife adapted to pass through a cup-shaped contain-er in close proximity to the inner wall of the container and through the body of the fruit held therein adjacent the peel and wherein the cutting edge of the knife lies substantially flush with the inner face of the blade, the outer face of the blade being bevel-ed rearwardly at the cutting edge whereby the pressure upon the peel and the pull upon the body of the fruit is directed outwardly of the fruit and against the wall of the cup at and just ahead of the cutting edge of the knife.

It will also be observed that in my improved knife the transverse curvature on the inner surface of the knife is so shaped as to be a segment of substantially a true circle with varying radii perpendicular to the axis of rotation of the knife and the center of these radii coincide with and fall upon the center line of the axis of rotation.

Figure 6 is a side view of one of the blocks it! to which the blade I0 is attached for rotation. The block I8 receives a rotating shaft 20 in its shaft opening I 9. Any suitable fastening means, as a pin, may be used therebetween. A lug 2| projecting from the block has an inclined face traversed by a groove 22 into which groove the end of the blade beyond its cutting edge may be seated. A cap screw 23 passing through the notch ll detachably holds the blade in place upon the block E8. The other end of the blade l0 may be similarly attached to a complemental block l8, not shown.

By shaping the inner face of the blade [0 about the axis of rotation A, the knife when passed through the body of a fruit, will glide freely along the periphery of the portion of the fruit from which the peel has been severed, the body of the knife not crowding or distorting the body of the fruit from which the peel is separated. The trailing section of the face of the blade will be at the same radius from the axis of rotation of the blade as the leading and cutting edge portion and hence there will be no tendency for the body portion to squeeze or bruise the useful section of fruit. The radius at which the outer face of the knife swings or rotates is such as to carry that face a small fraction of an inch from the inner wall of the cup that holds the fruit.

The claims in this application are limited to the novel features of construction of the peeling knife per se.

What is claimed as new and is desired to be secured by Letters Patent of the United States is:

1. A peeling blade having an axis about which it is turned comprising a relatively narrow blank strip of metal having a cutting edge shaped to follow the contour of a peripheral element extending antipodally of an article to be peeled, the axis of rotation of said blade subtending such edge, the inner face of said strip being dished transversely of and substantially coextensively of the length of said edge so that each transverse section thereof focuses upon the respective point in such axis from which it is normally disposed, and the outer face of the strip converging upon the inner face to provide the cutting edge flush with such inner face.

2. A peeling blade for peeling half fruit, and having an axis of rotation about which it is turned, said blade comprising a relatively narrow blank strip of metal curved to conform to the curvature of the fruit to be peeled, the inner face of the strip transversely of the length of the strip being concentric to the axis of rotation of the blade, a portion of the outer face of the blade being disposed to form a relatively blunt angle with the inner face of the blade to provide a cutting edge substantially at the inner face of the blade and coinciding substantially with the axis of rotation of the blade.

MARK EWALD. 

